MEMBRANE JUNCTION Flashcards
Large, automatic, bidirectional
Functional unit
Protein subunits
Allow ___ messenger
Gap junction
Connexon
Connexins
Small, voltage sensitive
Tight junctions
Links to cytoskeleton
Non discriminatory
Desmosomes
Cells communicate by releasing extracellular signal molecules
___ ability to coordinate cellular activity and function.
Signal transduction
Cell signaling
8 types of cellular response
Movement
Apoptosis
No response
Synthesis
Differentiation
Secretion
Metabolism
Multiplication
Direct phone call
Via gap junction
Electrical signaling
Direct contact between adjacent cells
F2f communication
Cell-cell communications
Signal released in extracellular compartments.
Ex. Hormone
Chemical signaling
Signal travels in bloodstream.
Release signal affects cell of origin.
Signal is released by one call
Endocrine
Autocrine
Paracrine
For lipid soluble messenger.
For lipid insoluble messenger
Cellular receptors
Intracellular receptors
Plasma membrane receptors
Longer effects
Lipophilic
Inactive receptors
Intracellular receptors
STEROID RECEPTORS
Released by
kidneys
Adrenal cortex
Gonads
Vitamin D
Cortisol
Sex hormones
Received signals in cytoplasm.
Found inside nucleus
Cytoplasmic/ gated receptors
Nuclear receptors
Ligand gated ion chanels
Influx and efflux
Ion channels
Bind guanine nucleotides
Central role in many enzyme linked receptors.
Regulate activity of other proteins.
Composed of 7 transmembrane
G protein
Monomerc
Heterotrimeric
GPCRs
Site of ligand binding
Attached heterotrimeric subunit
Extracellular domain
Intracellular domain
2 types of receptors
ANP + GC receptors
2 types
Guanylate cyclase receptors
Tyrosine kinase receptors
GCP
Transmembrane GCR (activated by atrial natriuretic peptide)
soluble GCR (activated by nitric oxide)
Amplification of __ binding event
Mechanism
Signal receptor ^
¥
Activation of inositol 1,4,5, triphosphate (___)
signal binds (process)
Phospholipase C
GPCR > GDP > a subunit > hydrolysis > produce IP3
Activation of adenylyl cyclase pathway
Structurally composed of 2 regulatory and 2 catalytic subunits.
Cyclic amp
PKA
Stimulus involved is light
Absorbs light
Activate G protein via alpha T
Cyclic GMP
Rhodopsin
Transducin
MAPK
Pathway;
Mitogen-activated protein kinase
Ligand bind to TK > induce TK activity > Grb2 phosphorylated> SOS activates > activate MAPKK> phosphorylation to MAPK > translocate nucleus> stimulates gene transcription
P13/AKT
pathway
Inositol (3,4,5) triphosphate
Ligand binds to TK > phosphorylated attaches P13K >PIP2 phosphorylated to become P13> PIP3 + PDK1 and AKT> PDK1 activates AKT
Jak / stat
Pathway
Janus associated kinase
Cytokines > dimerization>activation loops> JAK(activated)> phosphorylated> tyrosine phosphorylated > STAT dissociates + activated > STAT binds to Tyrosine-P> translocated cell nucleus> target gene activated
